This cardiopulmonary program is primarily concerned with the interplay between respiration and circulation in health and in disease. Theresearcheffots fall into five distinct categories: the regulation ofventilation, the regulation of the circulation, the pathogenesis of arteriosclerosis, myocardial performance, and hemodynamics. There is an effective interplay among the various investigators so that techniques in one specialized area are quickly adapted for researchand cinical purposes in other areas. For example, the deveopment of new tests for determining the sensitivity of the respiratory center has led to screening methods which apply to the development of corpulmonale and heart failure. During the current year, new investigatorshave joined the program bringing new tecniques and conceptswhich will be useful in developing the missions of the program with respect to research in cardiopulmonary disease.